"Millions of poor, disadvantaged students are trapped in failing schools."

So said President Trump at the White House recently. It's a familiar lament across the political spectrum, so much so that you could almost give it its own acronym : PKTIFS (Poor Kids Trapped In Failing Schools).

Where there's no consensus, however, is on the proper remedy for PKTIFS.

The Obama administration's signature proposal was the School Improvement Grant. This was a $7 billion attempt to turn around struggling schools with some combination of replacing personnel, overhauling the curriculum, renewed teacher support and other practices.

It was one of the largest federal education grant programs ever created. There was just one problem. As a department-commissioned independent review concluded just as Obama was leaving office, it didn't work. "Overall, across all grades, we found ... no significant impacts on math or reading test scores, high school graduation, or college enrollment."

President Trump, and his education secretary, Betsy DeVos, are largely focused on the T for "trapped" part of the problem. They talk about creating escape routes, largely by expanding charter and voucher programs.

Richard Kahlenberg has spent decades stumping for a third way. His idea: Create public schools that are more integrated. He helped innovate the use of social and economic indicators to do that — instead of race and ethnicity, the use of which is prohibited by a 2007 Supreme Court decision.

His strategy could be summed up as: Give poor kids the opportunity to attend school with not-so-poor kids.

The organization where he's a senior fellow, the Century Foundation, keeps track of 100 districts and charter schools around the country that are currently trying various integration strategies. The foundation recently released a paper with nine case studies: New York; Chicago; Dallas; Hartford and Stamford, Conn.; Jefferson County, Ky.; Eden Prairie, Minn.; Champaign, Ill.; and Cambridge, Mass.

Though it may seem quixotic, Kahlenberg says there's reason to be optimistic about integration policies. After all, we've tried everything else.

"I was critical of [former Education Secretary Arne] Duncan when he proposed school turnaround and ignored segregation," Kahlenberg says. "When they announced federal turnaround efforts, Duncan bragged about the fact that in Chicago, 'We had the same kids but we changed the adults.'

"On one level I understand that," he continues. "Even in segregated environments, there are positive things you can do for kids. Yet, it seemed to be taking off the table this really powerful tool that 50 years of research suggest can make a big difference in students' lives."

NPR Ed talked to Kahlenberg about this body of research. First, about the case for creating schools that are both economically and racially integrated, and second, on how to go about that.

What's the educational case for integration?

There are three reasons: the kids, the parents and the teachers.

Kids who have big dreams and are expecting to go on to college are less likely to cause disruption, cut classes and are more likely to be academically engaged.

On average, those peers are found more often in economically mixed than in high-poverty schools.

It's also an advantage to be in a classroom where your peers are high-achieving. For example, children of professionals have bigger vocabularies on average than low-income students, and that will rub off.

As for the parents, again, not attaching any blame, but middle-class parents are more likely to be PTA members and volunteer in class. That parental involvement benefits every child in a school.

And finally, the teachers deemed more effective are more likely to be found in economically mixed schools. That has to do with those first two factors. It's easier to teach in a school with fewer discipline issues and with parents who are there to help out.

OK, but what about the middle-class students? Is there evidence that it won't hurt them to attend a more diverse school?

Yes, the research shows that middle-class students tend to do as well academically in economically mixed schools. But more than that, there's emerging research to suggest that, indeed, middle-class students benefit from both economic and racial diversity. As we become a majority-minority nation, more millennial parents are recognizing that it's a skill to thrive in diverse environments, and employers are looking for people who can get along with individuals from all different backgrounds.

That said, most of the criteria we use to judge school performance, like test scores, are tightly correlated with class. How do you get parents who are privileged to choose an economically mixed school?

I think it's an exciting moment for magnet schools. When magnet schools offer different themes and pedagogical approaches, they're providing things that are popular with enough parents that it opens the door to the reality of school integration in a way that's politically palatable.

[DeVos spoke recently at the Magnet Schools of America conference, where she highlighted the role of magnet schools in reducing segregation. This recent review of research on magnet schools shows both positive and null results on academic performance, although most studies support higher graduation rates at magnet schools.

In New York City, where I live, as your report notes, 77 percent of students live in poverty. How do you create economically mixed schools if there aren't enough middle-class kids to go around?

I worked with Chicago Public Schools on their socioeconomic integration plan. The district is 85 percent low-income. My recommendation was not to ensure that every school was 85 percent low-income, because high-poverty schools are bad for students. In Chicago what they've done is to begin with magnet and selective-enrollment schools. You want to create a virtuous cycle where people can see examples of success.

[According to the recent report, Chicago's selective enrollment or "exam high schools" are much more racially balanced than their counterparts in Boston and New York City. And in those Chicago schools students from all backgrounds are keeping up academically and graduating at very high rates.]

It almost sounds like a chemistry experiment — you have to control the conditions very carefully and titrate your mixture until it hits that tipping point.

The long-term aspiration is that, as you develop more socioeconomically integrated schools, that the overall demographics of the public school system could shift. We saw that in Cambridge: Over time, more middle-class and white people came back into the district, stopped using private schools and stopped moving away once their kids got to be a certain age.

How good are the chances of seeing more districts try integration in this policy climate?

Most of the focus around choice has been on charter schools, and I think now, maybe after an election that revealed these tremendous divisions by race, class and gender, there's an opportunity to harness the interest in choice for a program that will actually bring kids of different backgrounds together, and heal some of those divisions that we saw come out during the election.

Now, at a programmatic level, there's lots of reasons for someone like me to be depressed, because DeVos and Trump haven't talked [much] about the benefits of school integration. But you can see lots of progress on the issue of school integration that isn't directed by the feds. ... So, rather than continuing to pound our heads against the wall in finding new ways to make separate but equal work, we could rediscover this other approach that actually is having really strong results.